Suffix Solution

#include<bits/stdc++.h>

using namespace std;

int pls(int a, int b, int MOD) {
    a += b;
    if (a >= MOD) a -= MOD;
    return a;
}

int mns(int a, int b, int MOD) {
    a -= b;
    if (a < 0) a += MOD;
    return a;
}

int prd(int a, int b, int MOD) {
    return 1ll * a * b % MOD;
}

const pair<int, int> mods = {1e9 + 7, 998244353}, bases = {179, 239};

pair<int, int> operator+(pair<int, int> a, pair<int, int> b) {
    return make_pair(
            pls(a.first, b.first, mods.first),
            pls(a.second, b.second, mods.second)
            );
}

pair<int, int> operator-(pair<int, int> a, pair<int, int> b) {
    return make_pair(
            mns(a.first, b.first, mods.first),
            mns(a.second, b.second, mods.second)
    );
}

pair<int, int> operator*(pair<int, int> a, pair<int, int> b) {
    return make_pair(
            prd(a.first, b.first, mods.first),
            prd(a.second, b.second, mods.second)
    );
}

struct MyHash {
    vector<pair<int, int>> pref, pw;
    string s;
    int n;

    MyHash(string &_s) {
        s = _s;
        n = (int) s.size();
        pref.resize(n + 1, {0, 0});
        pw.resize(n + 1, {1, 1});
        for (int i = 1; i <= n; i++) {
            auto val = (int)(s[i - 1] - 'A' + 1);
            pref[i] = pref[i - 1] * bases + make_pair(val, val);
            pw[i] = pw[i - 1] * bases;
        }
    }

    pair<int, int> ask(int l, int r) {
        return pref[r] - pref[l] * pw[r - l];
    }
};

int hashesSolution(string &s) {
    string rev = s;
    reverse(rev.begin(), rev.end());
    MyHash HashS(s), HashRev(rev);
    int cnt = 0, N = (int) s.size();
    for (int len = 0; len <= N; len++) {
        if (HashS.ask(N - len, N) == HashS.ask(0, len) &&
            HashS.ask(len, N) == HashRev.ask(0, N - len)) {
            cnt++;
        }
    }
    return cnt;
}

int stupidSolution(string &s) {
    int cnt = 0;
    int N = (int) s.size();
    string rev = s;
    reverse(rev.begin(), rev.end());
    for (int len = 0; len <= N; len++) {
        string t;
        for (int i = N - len; i < N; i++) t += s[i];
        t += rev;
        bool fl = true;
        for (int i = 0; i < (int)t.size() / 2; i++) {
            if (t[i] != t[(int)t.size() - i - 1]) {
                fl = false;
                break;
            }
        }
        cnt += (int) fl;
    }
    return cnt;
}

mt19937 rnd(time(nullptr));

string getRandomString(int len) {
    string res;
    for (int i = 0; i < len; i++) {
        int val = rnd();
        val = abs(val) % 52;
        if (val < 26) res += (char)(val + 'A');
        else res += (char)(val - 26 + 'a');
    }
    return res;
}

string correct(string &s) {
    string t;
    if (s.empty()) return "#";
    t += s[0];
    for (int i = 1; i < (int) s.size(); i++) {
        t += '#';
        t += s[i];
    }
    return t;
}

vector<int> manacher(string &s) {
    int n = (int) s.size();
    vector<int> d(n, 1);
    int l = 0, r = 0;
    for (int i = 1; i < n; i++) {
        if (i < r)
            d[i] = min(r - i + 1, d[l + r - i]);
        while (i - d[i] >= 0 && i + d[i] < n && s[i - d[i]] == s[i + d[i]])
            d[i]++;
        if (i + d[i] - 1 > r)
            l = i - d[i] + 1, r = i + d[i] - 1;
    }
    return d;
}

int manacherSolution(string &s) {
    string rev = s;
    reverse(rev.begin(), rev.end());
    string t = rev + s;
    t = correct(t);
    auto d = manacher(t);
    int cnt = 0, n = (int) t.size();
    for (int i = n / 2; i < n; i++) {
        if (i + d[i] == n && i - d[i] <= n / 2) {
            cnt++;
        }
    }
    return cnt;
}

void Fast() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
}

signed main() {
    Fast();
    string s;
    cin >> s;
    cout << manacherSolution(s);
//    for (int len = 0; len <= 500; len++) {
//        for (int i = 0; i < 100; i++) {
//            string s = getRandomString(len);
//            int answer = hashesSolution(s), result = manacherSolution(s);
//            if (answer != result) {
//                cout << s << "\n" << result << " " << answer << endl;
//            }
//        }
//    }
}